A little girl is rounded up in 1942 Paris with her family and a woman in modern-day Paris investigates her story in Sarah’s Key, a choppy movie based on a novel of the same name.

In July 1942 Paris, we see Sarah Starzynski (Melusine Mayance) playing with her little brother Michel (Paul Mercier) when police men (French police men, it should be noted, not Germans) come to the door of the family’s apartment. They ask Sarah’s mother (Natasha Mashkevich) questions about her husband (Arben Bajraktaraj) and her son, and Sarah, in a moment of protectiveness, tells her little brother to hide in a wall closet (the wall slides closed and can be locked with a key; from the outside, it doesn’t seem like there’s anything there but wall). Wait here, she says, giving him some water, and I’ll come for you. The policemen tell her family to pack, and soon Sarah, her mother and her father are herded into a stadium awaiting, well, something. They don’t know what, exactly, though we know it isn’t good.

In modern-day Paris, Julia Jarmond (Kristin Scott Thomas) is an American journalist living in Paris with her husband Bertrand Tezac (Frederic Pierrot) and their teenage daughter Zoe (Karina Hin). She’s writing a story about the anniversary of the Vel’ d’Hiv Roundup, which is what the roundup that included the Starzynskis has come to be known as. With the roundup and its aftermath (particularly how people quickly moved into the homes the Jewish Parisians had been forced out of) on her mind, Julia starts to get curious when she learns that the Tezac family apartment that she and Bertrand are having renovated was obtained in August 1942. It takes the movie much longer to get to the conclusion we in the audience reach almost immediately: the apartment that is to become Julia’s family home is the same one where Sarah’s family lived in before they were taken away.

The movie intertwines these two stories: Sarah and her family spending several miserable days in the stadium before being moved to yet another camp; Julia digging into the apartment’s past and trying to find out what happened to the Starzynskis, particularly the children. At the same time, Julia’s personal life starts to unravel when, several years after she and her husband stopped trying for a baby, she learns that she is pregnant.

This pregnancy plot is poignant but it still feels squished in. It’s like a puzzle piece that almost fits but has to be crammed in and then doesn’t quite match with those around it. The result is that it makes all the elements of the story feel a little disconnected from each other. And, while perhaps interesting and even at times engrossing, these different plot pieces never quite come together as one coherent thing.

I knew very little about the Vel’ d’Hiv Roundup (I think I have some vague memory of the official government apology in the 1990s shown late in the film) so the details of that incident were interesting. And the story of the Starzynskis is heartbreaking, all the more so because we in the audience can guess their situation and what awaits them. Thomas gives Julia, who could have been little more than a glorified narrator, some heart and personality. We can understand why she becomes engrossed in the Starzynskis’ story and why the thought of living in their apartment starts to bother her.

The rest of her story — the pregnancy, her relationship with her husband — is where the movie starts to feel wobbly. Already a bit choppy as we move back and forth from the 1940s to the present day, the movie feels even more fragmented when we’re going from the horrors of the Holocaust to Julia’s personal life and back again.

Like many an imperfectly adapted novel, Sarah’s Key seems like, if nothing more, a good advertisement for the book. Perhaps there some of the disjointedness of the story comes together. B-

Rated PG-13 for thematic material including disturbing situations involving the Holocaust. Directed by Gilles Paquet-Brenner with a screenplay by Paquet-Brenner and Serge Joncour (from the novel by Tatiana De Rosnay), Sarah’s Key is an hour and 53 minutes long and distributed by The Weinstein Company.